System and method of UE-centric radio access procedure

1. A method comprising: sending, by a network node to a first user equipment (UE) that is in an active state, a UE identifier (UE ID) that is uniquely assigned to the first UE; sending, by the network node to the first UE that has transitioned from the active state to a first state, an indication of a downlink (DL) data transmission on a DL notification channel, the indication being addressed to the first UE using the UE ID assigned to the first UE in the active state, the first state supporting a reduced set of UE functionality compared to the active state and the first state supporting data communication between the first UE and the network node; and sending, by the network node to the first UE that is in the first state, DL data in a grant-free DL channel, the data being transmitted with the UE ID assigned to the first UE in the active state.

2. The method according to claim 1 , further comprising, after sending the indication: receiving, by the network node from the first UE that is in the first state, information associated with an additional measurement.

3. The method according to claim 1 , wherein the indication indicates that a state transition to the active state is required.

4. The method according to claim 3 , wherein the network node sends the DL data to the first UE that is in the first state on the grant-free DL channel within a defined time duration after the indication is sent.

5. The method according to claim 3 , further comprising, after sending the indication: receiving, by the network node from the first UE that is in the first state, a UE centric sequence.

6. The method according to claim 5 , further comprising, after receiving the UE centric sequence: sending, by the network node to the first UE that is in the first state, a message confirming that the state transition to the active state should proceed.

7. The method according to claim 5 , wherein the UE centric sequence is received on a defined uplink resource.

8. The method according to claim 1 , wherein the indication is sent when DL data to be sent exceeds a capacity of the grant-free DL channel.

9. The method according to claim 1 , wherein the DL notification channel is shared by multiple UEs including the first UE.

10. The method according to claim 1 , wherein the first state supports a data transfer connectivity without dynamic resource allocation grant from the network node.

11. An apparatus comprising a processor coupled with a memory, the processor configured to: send, to a first user equipment (UE) that is in an active state, a UE identifier (UE ID) that is uniquely assigned to the first UE; send, to the first UE that has transitioned from the active state to a first state, an indication of a downlink (DL) data transmission on a DL notification channel, the indication being addressed to the first UE using the UE ID assigned to the first UE in the active state, the first state supporting a reduced set of UE functionality compared to the active state and the first state supporting data communication between the first UE and the network node; and send, to the first UE that is in the first state, DL data in a grant-free DL channel, the data being transmitted with the UE ID assigned to the first UE in the active state.

12. A method comprising: receiving, from a network node by a first user equipment (UE) that is in an active state, a UE identifier (UE ID) that is uniquely assigned to the first UE; monitoring, from the network node, by the first UE that has transitioned from the active state to a first state, a downlink (DL) notification channel for an indication of a DL data transmission, the indication being addressed to the first UE using the UE ID assigned to the first UE in the active state, the first state supporting a reduced set of UE functionality compared to the active state and the first state supporting data communication between the first UE and the network node; determining, by the first UE that is in the first state, a UE state according to whether the indication is received or not; and receiving, by the first UE from the network node, DL data according to the determination, the data being transmitted with the UE ID assigned to the first UE in the active state.

13. The method according to claim 12 , wherein the determining comprises: determining, by the first UE that is in the first state, to maintain the UE state in the first state if the indication is not received.

14. The method according to claim 13 , wherein receiving DL data comprises: receiving, by the first UE that is in the first state, the DL data over a grant-free DL channel.

15. The method according to claim 12 , wherein receiving DL data comprises: within a defined time duration after the indication is received, receiving, by the first UE that is in the first state, DL data in a grant-free DL channel.

16. The method according to claim 12 , wherein the determining comprises: determining, by the first UE that is in the first state, to transition the UE state to the active state if the indication is received.

17. The method according to claim 16 , wherein the received indication indicates that a state transition to the active state is required.

18. The method according to claim 16 , further comprising: transitioning, by the first UE that is in the first state, the UE state to the active state.

19. The method according to claim 18 , further comprising, before the transition: sending, to the network node, by the first UE that is in the first state, a UE centric sequence in response to the received indication.

20. The method according to claim 19 , further comprising, after sending the UE centric sequence: receiving, from the network node, by the first UE that is in the first state, a message confirming that the state transition to the active state should proceed; wherein the first UE transitions the UE state to the active state after receiving the message.

21. The method according to claim 19 , wherein the UE centric sequence is sent on a defined uplink resource.

22. The method according to claim 18 , wherein receiving DL data comprises: receiving, by the first UE that is in the active state, DL data that exceeds a capacity of a grant-free DL channel.

23. The method according to claim 12 , wherein the DL notification channel is shared by multiple UEs including the first UE.

24. The method according to claim 12 , further comprising: receiving, by the first UE, information associated with the downlink notification channel assigned to the first UE during an initial access procedure of the first UE or when the first UE goes into the first state.

25. The method according to claim 12 , wherein the first state supports a data transfer connectivity without dynamic resource allocation grant from the network node.

26. An apparatus comprising a processor coupled with a memory, the processor configured to: when the apparatus is in an active state receive, from a network node, a user equipment identifier (UE ID) that is uniquely assigned to the apparatus; when the apparatus has transitioned from the active state to a first state, monitor a downlink (DL) notification channel for an indication of a DL data transmission from the network node, the indication being addressed to apparatus using the UE ID assigned to the apparatus in the active state, the first state supporting a reduced set of apparatus functionality compared to the active state and the first state supporting data communication between the apparatus and the network node, and determine a UE state according to whether the indication is received or not; and receive DL data according to the determination from the network node, the data being transmitted with the UE ID assigned to the first UE in the active state.